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A266071
Binary representation of the middle column of the "Rule 3" elementary cellular automaton starting with a single ON (black) cell.
5
1, 10, 100, 1001, 10010, 100101, 1001010, 10010101, 100101010, 1001010101, 10010101010, 100101010101, 1001010101010, 10010101010101, 100101010101010, 1001010101010101, 10010101010101010, 100101010101010101, 1001010101010101010, 10010101010101010101
OFFSET
0,2
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
FORMULA
G.f.: (1 - x^2 + x^3)/(1 - 10*x - x^2 + 10*x^3). - Michael De Vlieger, Dec 21 2015
a(n) = floor(991*10^n/990). - Karl V. Keller, Jr., Oct 09 2021
EXAMPLE
From Michael De Vlieger, Dec 21 2015: (Start)
First 8 rows at left with the center column values in parentheses, and at right the binary value of center column cells up to that row:
(1) -> 1
1 (0) 0 -> 10
0 0 (0) 1 0 -> 100
1 1 1 (1) 0 0 1 -> 1001
0 0 0 0 (0) 0 1 0 0 -> 10010
1 1 1 1 1 (1) 1 0 0 1 1 -> 100101
0 0 0 0 0 0 (0) 0 0 1 0 0 0 -> 1001010
1 1 1 1 1 1 1 (1) 1 1 0 0 1 1 1 -> 10010101
(End)
MATHEMATICA
Table[SeriesCoefficient[(1 - x^2 + x^3)/(1 - 10 x - x^2 + 10 x^3), {x, 0, n}], {n, 0, 19}] (* Michael De Vlieger, Dec 21 2015 *)
PROG
(Python) print([991*10**n//990 for n in range(50)]) # Karl V. Keller, Jr., Oct 09 2021
CROSSREFS
Cf. A266070, A081253 (decimal).
Sequence in context: A281730 A282954 A282984 * A118256 A351386 A102397
KEYWORD
nonn,easy
AUTHOR
Robert Price, Dec 20 2015
STATUS
approved